What do Atticus' beliefs about the possible threat that Bob Ewell poses to him suggest about Atticus
outlook on the world?

The sentence "Knox found that his warrior instinct had abandoned him" is an example of an indirect characterization.

Based on the author's characterization Henry Knox is a coward.

Explanation:

Henry Knox was the US secretary of war when the yellow fever plague struck, president George Washington put him in charge of the government and asked him to report to him regarding the spread of the disease.

However Henry Knox fled from the city after a few days in fear of the disease, and the author's slightly mocking tone suggests that his behavior was cowardly.

Indirect characterization is used to indicate what a character is like by describing their actions, appearance or speech. In describing the thoughts and actions of Henry Knox the author uses indirect characterization.